With the development of science and technology, flat panel display devices (e.g., liquid crystal display devices) have many advantages of high display quality, small volume, light weight and wide application range and thus are widely used in consumer electronics products such as mobile phones, laptop computers, desktop computers and televisions, etc. Moreover, the liquid crystal display devices have evolved into a mainstream display in place of cathode ray tube (CRT) displays.
In another aspect, the touch input device provides a new human machine interface and is more intuitive and humanity in use. Moreover, the touch input device can be integrated with a flat panel display device to constitute a touch panel, so that the touch panel is endowed with display and touch input functions.
Referring to FIG. 1, schematic waveform diagrams of multiple signals associated with a touch panel in the prior art are shown. In particular, a single frame period of the touch panel generally includes multiple gate line scan periods (FIG. 1 only shows two gate line scan periods for the purpose of illustration). As to the touch panel with a frame refreshing rate of 60 Hz and a native resolution of 1366×768, a single gate line scan period, i.e., the time duration from a falling edge of a pulse in a scan control clock signal YCLK to a rising edge of the next pulse in the scan control clock signal YCLK may be set as 20 microseconds (μs). In some gate line scan periods, a source driving circuit in the touch panel would provide data lines with display data for charging or discharging corresponding pixels to respective data voltages, a time length of such charging or discharging operation can termed as data coupling time (e.g., about 13 μs).
Generally, a common voltage on a common electrode in the touch panel would be caused disturbance during the data coupling time, which would influence the touch sensors in the touch panel and therefore the touch driving pulse (e.g., having a pulse width of about 2.5 μs) must be non-overlapped with the data coupling time. However, since the data coupling time is excessive long and the amounts of touch driving pulse in respective gate line scan periods are the same in the prior art, resulting in the touch control scanning frame rate of the touch panel is excessive low and thus the touch detection sensitivity is degraded. In addition, as seen from FIG. 1, as to the situation of an angling control signal YV1C being provided to change the signal waveforms on the respective gate lines, the touch driving pulse further must be non-overlapped with a variation time (e.g., about 3.5 μs) of the angling control signal YV1C. Herein, the variation time is defined as the time duration from a rising edge of a certain pulse of the angling control signal YV1C to a rising edge of the nearest pulse of the scan control clock signal YCLK.